CTRL hole swallows garden

A 10m wide, 5m deep hole has swallowed two gardens, situated above a tunnel being constructed on contract 240 on the Channel Tunnel Rail Link (CTRL) in East London, England, on 8 February.

Thirty-five residents of Lavender Street, Stratford, whose houses were close to the collapse, were evacutated and spent Saturday night in a hotel. Most returned home the following day. Nobody was injured.

The hole was swiftly filled with concrete by the contractor, Costain/Skanska (UK)/Bachy Soletanche JV, which has stopped work until further detailed surveys are carried out.

In a joint statement, Rail Link Engineering and Union Rail said: "Tunnelling will not recommence until CTRL engineers and the safety authorities are satisfied that it is safe to do so." They also said: "The tunnel has not been affected by the subsidence and is in a safe and stable condition with the ground above fully supported." It is believed that the tunnel may have intersected one or more disused wells, causing the collapse.

Contract 240 consists of two 4.7km long tunnels, each with a 7.15m internal diameter, bored between Stratford Box and Barrington Road in Newham. The US$196M contract is being constructed with two Wirth EPBMs, the first of which set out in September 2002.

See March's issue of T&TI for more details